In particular in the case of HPLC (high performance liquid chromatography) processes, in which operation is carried out at very high pressures, high requirements are made of the seals. Belonging to processes of this type are, for example, pumps, in which pressures of over 100 MPa occur. Although attempts have been made in the prior art to assist a satisfactory sealing action by way of a manufacturing tolerance which is as narrow as possible, the high pressures which occur have up to now not permitted any satisfactory solutions. Embodiments are known, in which annular sealing elements are prestressed in the axial direction, in order to achieve a desired sealing action. The increased internal pressure which occurs during operation leads, however, to the components which are sealed with respect to one another being pressed apart, with the result that the prestressing pressure which is introduced into the seal and therefore the sealing action also decrease. Correspondingly, the prestressing pressure previously has to be set to be sufficiently high above the operating pressure to be expected.
Elements for cleaning or mixing liquids are frequently also used within high pressure systems of this type. They have to be exchangeable, with the result that a satisfactory sealing action of the components which receive them and can be released from one another is required. At the same time, the filter or mixer within the system also has to be sealed in such a way that no medium can flow past it, but rather exclusively through it. Here, the filters or mixers which are used in HPLC technology frequently have manufacturing tolerances which are to be taken into consideration in the sealing action. For instance, sintered metallic frits are known which have a specific porosity and pore width. They can be disk-shaped with a diameter up to the centimeter range and a thickness of a few millimeters.
DE 38 38 692 A1 has disclosed an arrangement for sealing a rod which is moved to and fro, in which arrangement a sealing ring is seated in a groove and circumferentially loads the rod with one edge for sealing purposes. A deformable clamping ring loads the sealing ring in the radial direction. It was therefore an object of the invention to provide a method for sealing and a device for carrying out the method, in order for it to be possible to achieve a reliable sealing action in a simple way even at very high operating pressures.